If a gas pressure gauge reads 15 mm Hg, what is the pressure in atmospheres?

Question

7205 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-06-12T02:33:13

0,020 atmospheres

760 mm Hg = 1 atmosphere.

$\frac{15}{760} = a t m o s p h e r e$ $15/760 = atmosphere$

# 15/760 = 0.0197368 atmospheres rounding off to 2 significant digits gives

0.020 atmospheres

Answer 2 · 2017-06-12T02:35:19

$0.020$ $0.020$ $atm$ $"atm"$

To convert between millimeters Mercury ( $mm Hg$ $"mm Hg"$ ) and atmospheres ( $atm$ $"atm"$ ), we use the conversion factor

$\frac{1 atm}{760 mm Hg}$ $(1"atm")/(760"mm Hg")$

That is, $1$ $1$ atmosphere equals $760$ $760$ millimeters Mercury.

Using dimensional analysis, we can convert the given pressure:

$15$ $15$ $cancel("mm Hg")((1"atm")/(760cancel("mm Hg"))) = color(red)(0.020$ $color(red)("atm"$

$15$ $"mm Hg"$ is equal to $0.020$ $"atm"$ , rounded to $color(blue)(2$ significant figures, the amount given in the problem.